Lubricating system



March 23, 1937. F. E. DAYES LUBRICATING SYSTEM File d Aug. 9, 1933' 2 Sheets-Sheet 1 \NvEN'roz Fzzoemcz E. DAYES ATTOENEY March 23, 1937. F. E. DAYES 2,074,373

LUBRICATING SYSTEM Filed Aug. 9, 1933 2 Sheets-Sheet 2 \NVENTOE Fzzoamcz E. DAYES ATTOENEY,

Patented Mar. 23, 1937 .LUBRICATING SYSTEM Frederick E. Dayes,Philadclphia, Pa., assignor to American Car and Foundry Motors Company, New York, N. Y., a corporation of Delaware Application August 9,

6 Claims.

This invention relates generally to lubricating systems for reciprocatory mechanisms, and more particularly to lubricating systems for horizontally disposed pistons and cylinders of internal combustion engines.

In the operation of engines with horizontal cylinders, much difficulty has been experienced in maintaining a film of oilbetween thecylinders and pistons. It has beenfound that if the bearing surfaces between the top of the piston and cylinder are subjected to any considerable thrust during the expansion stroke, the lubricant disappears from these bearing surfaces and the piston, which is usually of softer material than the cylinder, becomesscored and damaged.

An object of the invention is to provide for introducing a, lubricantbetween the bearing surfaces of a piston and cylinder whilethey are in operation.

It is also an'object of the invention to provide a for maintaining a film of oilbetween the bearing surfaces and on the pressure side of a reciprocating piston and cylinder.

The invention accordingly is disclosed in the embodiment thereof .shown in the accompanying drawings, and comprises features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should .be had to the following detailed description taken in connection with the accompanying drawings,

in which Figure l 'is a View in vertical section of a lubricating system constructed in accordance with the invention.

Figure 2 is a View in vertical section taken along the line 2-2 of Figure 1 showing details of thestructure.

Figure 3 is a view in vertical section taken along the line 33 of Figure l and showing'the piston at the inner end of its stroke.

Figure 4 is an enlarged view in vertical section of a portion of the lubricating system showing details of the structure; and

Figure-5 is adiagrammatic view of a piston and cylinder.

Referring now to the-drawings, and-Figures 2 and 3 in particular an engine block ID of any well-known type is illustrated with :,a. cylinder is sleeve -.|=I disposed therein. .The=,cylinde,risleeve 1933, Serial No. 684,336

is spacedfrom the bIock forming a passageway l2 for a cooling medium such as water.

The outer end of the sleeve I 1 extends into the crankcase l3 and has its inner edge bevelled as shown at 14. The distance that the outer end of the cylinder sleeve extends into the crankcase will depend on the design of the engine. In an engine of well-known make, selected for experimental purposes, it wasfound that the cylinder sleeve extended one and one-half inches clear of the block into the crankcase.

A piston I5 of any well-known type provided with bearing rings and oil rings, is disposed in the cylinder sleeve II for reciprocatory movement, and connected to the crank shaft l6 through a connecting rod l1. As illustrated in Figure 3, when the piston l5 reaches the end of 7 its movement to the left, its rear portion projects beyond the cylinder sleeve II into the crankcase.

The functioning and advantages of the present lubricating system may be explained best by setting forth the conditions to be met. Referring 'to Figure 5, when a charge is fired, the piston I5 is actuated to the left. In moving the piston an actuating force is delivered through the connecting rod I! to the crank shaft l6 which is rotated-in the direction indicated by the arrow heads. The actuating force is continuously 0pposed by a reactive force in the direction of the arrow N. This reactive force will be continuously delivered-while the crank shaft is turning through The reactive force delivered to the pivotal connection between the piston l5 and connecting rod ll at any instant may be resolved into components which extend along vertical and horizontal lines. As will be readily appreciated, when the connecting rod l! is in the position indicated by the dot anddash lines in Figure 5, the vertical component of the force delivered is large causing considerable pressure between the bearing surfaces of the piston and cylinder. The vertical pressure acting as it must at the pivot end will cause a slight tilting of the piston thus putting the heaviestbearing pressure, which occurs during the power stroke, on the rear'upper portion of the piston. This pressure, together with the action of gravity, will cause the oil to flow downwardly in the cylinder with the result that when only the ordinary methods of lubrication are employed a film of oil is not maintained between the upper'face' of the piston especially at its rear portion and the coacting face of the cylinder.

In the present lubricating-system, in order 'to maintain-afilm of oilon the-pressure sideof the piston and between the piston and the cylinder, a lubricant is introduced between the bearing surfaces to the rear of the hearing or piston rings and distributed by the piston. Introducing the lubricant at this point insures that the upper rear portion of the piston, where the greatest pressure falls, will receive the bulk of the lubricant and also provide sufiicient lubricant for the rings to insure their proper protection yet without carrying an excess of lubricant into the combustion chamber. The lubricant may be introduced between the bearing surfaces from more than one point.

In the preferred embodiment illustrated, advantage is taken of the fact that the cylinder sleeve extends into the crankcase making it possible to gain access to the bearing surfaces between the piston and cylinder without entering through the water jacket l2. An opening I8 is provided in the end of the cylinder sleeve which extends into the crankcase l3. This opening is preferably provided in alignment with the center line of the top of the cylinder sleeve, and as far from. the end of the sleeve as possible. The size 01 the opening |8 will depend on the lubricating conditions to be met but is of sufficient size as to form an oil pocket or reservoir which is positively filled with oil when the piston is in the outer position shown in Fig. 3 and from which oil under atmospheric pressure is carried by the inwardly moving piston to insure proper cylinder wall lubrication.

A threaded opening L9 is provided in the crankcase in alignment with the opening |8 in the cylinder sleeve A threaded fitting 2|) through which oil may be supplied is screwed into the opening IS with its inner end spaced fro-m opening or pocket I 8 in order that any excess oil supplied may escape to the crankcase and not cause over-lubrication of the piston as would occur if the oil were supplied directly under high pressure. If oil is to be supplied to a number of cylinders in a multi-cylinder engine, a T-shaped fitting 20 will be selected so that it may be connected with other fittings to make a lubricant line for supplying all the cylinders.

The rate at which a lubricant is supplied to the reservoir or pocket and the bearing surfaces may be controlled by mounting a disc 2| having an orifice of the proper size in the lower end of the fitting 2|]. This disc 2| may be mounted in any suitable manner, as by welding it to a seat provided in the lower end of the fitting 20 and will insure the maintenance of the correct pressure in the supply line 24 for distribution of the lubricant.

In order to provide for feeding oil to all the cylinders from the same source, the T-fittings 20 are connected by means of pipe sections 22 and couplings 23, thus providing a common lubricant line. The couplings are so mounted that as they are threaded onto the ends of the fittings 20 they are pulled into tight engagement with the ends of the pipe sections 22. In this manner a lubricant line may be provided which will stand pressure. The outer end fitting is plugged in any suitable manner. The oil or lubricant for the cylinders may be supplied from any suitable source and in the case of engines provided with a force feed lubricating system, it will be supplied from the oil pump provided for pumping oil to the different bearings. In Figure 1 the oil or lubricant line comprising the fittings for supplying oil to the cylinders is connected to the source of lubricant supply, not shown, through a pipe 24.

Generally the pressure in a pressure lubricating system for internal combustion engines is in the neighborhood of from 80 to 100 lbs. per square inch. When such pressures are enmployed, in order to prevent the flow of an excessive amount of lubricant to the piston, an orifice very small in size will be required in the disc 2|. While discs such as 2| provided with small orifices may be employed to control the supply of oil to the piston, they are subject to plugging in many ways, for example, they may be plugged by deleterious matter in the oil, which may temporarily impair the usefulness of the system.

In the preferred embodiment of the system, the pressure of the lubricant is first stepped down to about 20 lbs. per square inch. In order to reduce the pressure of the lubricant before it reaches the disc 2|, a device 25 which in shop practice is called a metered fitting is employed. This metered fitting 25 is provided with an orifice of a predetermined size and is connected in the pipe 24 at its point of juncture with the casing 26 of the oil pump. When the lubricant flows through the orifice in the fitting 25 the pressure is reduced to a predetermined amount, say about 20 lbs. per square inch.

In order to deliver the same quantity of lubricant to the piston when the pressure on the lubricant is reduced from 80 to 20 lbs. per square inch, the size of the orifice in the disc 2| is increased. An orifice large enough to deliver the proper quantity of lubricant at 20 lbs. pressure is practically free from plugging.

In operation, oil is delivered through the orifice in the disc 2| and drops through opening or pocket l8 provided in the cylinder sleeve onto the surface of the piston when the latter is moving at the left end of its stroke, as illustrated in Figure 3. The oil delivered to the piston is within the area of the bearing surfaces and is distributed under atmospheric pressure between the upper contacting surfaces of the piston and cylinder.

The end of the skirt of the piston l5, as shown in Figures 2 and 3, is so rounded that it will not scrape or wipe the oil from the cylinder wall as it reciprocates. Therefore, the oil delivered to the piston l through the opening |8 forms a film of oil between the upper pressure bearing surfaces of the piston and cylinder, which is maintained at all times, since the oil is delivered continuously at substantially constant atmospheric pressure. The distribution of the lubricant under atmospheric pressure to the bearing surfaces insures the equal lubrication of the various surfaces practically independent of the rate of flow through the disc 2|- and as previously stated will prevent over-lubrication of the surfaces.

The oil delivered while the piston is at the right end of its stroke, as shown in Figure 2, flows around the cylinder wall or drops to the opposite side of the cylinder and is also distributed by the piston. The lubricating effect of this oil dropped on the cylinder is merely cumulative with the oil supplied to the cylinder by any other method that may be employed, such as a splash system.

Since certain changes may be made in the above construction and different embodiments of the invention may be made, without departing from the spirit and scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limited sense.

Having described my invention, What I claim as new and desire to secure by Letters Patent, is:

1. In a lubricating system for a horizontally disposed engine provided with a crank case and a block having a plurality of cylinders therein and pistons disposed in the cylinders for reciprocatory movement presentingbearing surfaces, in combination, a plurality of I T-shaped fittings each extending throughthe block into alignment with the upper center line of the respective piston and cylinder, the portion of said fittings which extends through the block being spaced from the respective cylinder and in direct communication with the crank case at all times, discs having orifices therein mounted in the fittings for controlling the fiow of lubricant, the cylinders having openings extending through them disposed in spaced relation but in alignment with the orifices in the discs through which lubricant at substantially atmospheric pressure may be introduced directly to the rear portion of the piston and between the bearing surfaces of the pistons and cylinders to insure correct and equal lubrication thereof, means connecting the T-shaped fittings outside the block to provide a lubricant pressure line to all the cylinders, and means for supplying a lubricant to said line.

2. In an internal combustion engine, a crank case, a cylinder block secured to the crank case, a cylinder sleeve within the cylinder block having one end portion extended into the crank case and provided with an opening therethrough adjacent the crank case and in communication therewith, a piston having piston rings at its forward end and reciprocable in said sleeve to a point where the rear portion thereof extends within the crank case and beyond the end portion of the sleeve, and means for supplying an excess of lubricant directly to the rear portion only of the piston and between the piston and sleeve comprising a lubricant fitting extending through the cylinder block and terminatin in spaced alinement with the opening in said sleeve, said fitting being connected with a source of lubricant supply and so spaced with respect to the sleeve opening as to permit escape of excess lubricant directly to the crank case.

3. In an internal combustion engine, a crank case, a cylinder block secured to the crank case, a cylinder sleeve within the cylinder block having one end portion extended into the crank case and provided with an opening therethrough arranged substantially at the juncture of the crank case and cylinder block, a piston having piston rings and reciprocable in said sleeve to a point where the rear portion thereof extends within the crank case and beyond the end portion of the sleeve, and means for supplying lubricant directly to the piston portions remote from the rings and between the piston and sleeve comprising a lubricant fitting extending through the cylinder block in alinement with the opening in said sleeve, said fitting being connected with a relatively high pressure source of lubricant supply, the fitting having the end thereof spaced from said opening and in direct communication with the crank case so as to permit the feeding of lubricant to the piston at substantially atmospheric pressure.

4. In an internal combustion engine of the horizontal type, a crank case, a cylinder block extending horizontally therefrom, a cylinder sleeve in the block having a portion intermediate its ends arranged in spaced relation with respect to the cylinder block to define a water jacket, one end portion of said sleeve projecting into the crank case and having an opening therethrough at the upper portion thereof, a piston reciprocable in the crank case, and a lubricant fitting extendingthrough the cylinder block adjacent the crank case, the fitting terminating in vertically spaced alignment with the opening and in direct communication with the crank case, said fitting being connected with a relatively high pressure source of lubricant supply so as to supply lubricant directly to the rear portion only of said piston and being spaced from said opening in order to supply lubricant at crank case pressure directly to the rear portion of said piston.

5. In an internal combustion engine of the horizontal type, a crank case, a cylinder block extending horizontally therefrom, a cylinder sleeve in the block having a portion intermediate its ends in spaced relation with respect to the cylinder block to define a water jacket, a portion of said sleeve projecting beyond the water jacket and into the crank case, the cylinder block and sleeve being formed with aligned openings spaced apart at the top of the assembly Within the range of excessive piston pressure and rearward of the water jacket, said openings being in direct communication With the crank case, and means for delivering an excess of oil under pressure through said cylinder block opening and through said sleeve opening upon said piston, said openings being spaced apart so as to permit direct discharge of excess lubricant to the crank case.

6. In an internal combustion engine of the horizontal type, a crank case, a cylinder block extending horizontally therefrom, a cylinder sleeve'in the block having a portion intermediate its ends in spaced relation with respect to the cylinder block to define a water jacket, a portion of said sleeve projecting beyond the water jacket and into the crank case, a piston reciprocable in the sleeve, the cylinder block and sleeve being formed with spaced aligned openings at the top of the assembly within the range of ex-- cessive piston pressure and rearward of the water jacket, said spaced openings being in direct communication with the crank case, and means for supplying an excess of lubricant under pressure to the piston through the aligned spaced openings including a source of lubricant supply, means for reducing the lubricant pressure adjacent its source, means for metering the lubricant at the point of discharge into said openings, said spaced openings permitting the feeding of lubricant to the piston at substantially atmospheric pressure and the discharge of excess lubricant to the crankcase.

FREDERICK E. DAYES. 

